Wildfire Zones: Redwood City vs San Mateo
How do wildfire zones rules compare between Redwood City, CA and San Mateo, CA?
San Mateo has fewer restrictions than Redwood City.
Redwood City, CA
San Mateo County
Unincorporated San Mateo County contains Moderate, High, and Very High Fire Hazard Severity Zones, with the Santa Cruz Mountains and coastal hills (La Honda, Pescadero, and similar) at the highest risk. Mapped zones trigger defensible space (PRC 4291), WUI building standards (CBC Chapter 7A), and real estate disclosure.
View full Redwood City rules →San Mateo, CA
San Mateo County
Portions of western San Mateo are mapped in CAL FIRE's Fire Hazard Severity Zones. New construction in these areas must meet Chapter 7A of the California Building Code for ignition-resistant construction. The San Mateo Consolidated Fire Department enforces fire hazard zone requirements.
View full San Mateo rules →Key Facts Comparison
| Fact | Redwood City | San Mateo |
|---|---|---|
| Zone classes | Moderate, High, Very High (CAL FIRE) | - |
| Highest-risk areas | Santa Cruz Mountains, coastal hills (La Honda, Pescadero) | - |
| Designating law | Government Code sections 51175-51189 | - |
| Defensible space (VHFHSZ) | 100 ft, PRC 4291 / Gov Code 51182 | - |
| WUI building standard | California Building Code Chapter 7A | - |
| Disclosure | Natural Hazard Disclosure required at sale | - |
| Fire Hazard Zones | - | Western hillsides — Moderate to High |
| Chapter 7A | - | Ignition-resistant construction required |
| Roofing | - | Class A fire-rated required |
| Eastern City | - | Not in fire hazard zones |
| Fire Dept | - | SM Consolidated Fire |
Highlighted rows indicate differences between cities.
Redwood City FAQ
Is unincorporated San Mateo County in a wildfire hazard zone?
Much of it is. The Santa Cruz Mountains and coastal hills, including communities such as La Honda, San Gregorio, and Pescadero, are mapped by CAL FIRE as High and Very High Fire Hazard Severity Zones. Check the county's interactive FHSZ map for your specific parcel.
What rules apply if my property is in a Very High zone?
You must maintain 100 feet of defensible space under PRC 4291 / Government Code 51182, new construction must meet California Building Code Chapter 7A wildfire-exposure standards, and you must disclose the FHSZ designation when selling.
Who provides fire protection in the unincorporated county?
CAL FIRE / San Mateo County Fire provides fire protection in the unincorporated areas and enforces defensible space and fire-code requirements. Contact the Fire Marshal at (650) 573-3846.
San Mateo FAQ
Is my San Mateo property in a wildfire zone?
Western hillside areas are in CAL FIRE Fire Hazard Severity Zones. The flat eastern areas near the bay are not. Check CAL FIRE maps or contact the fire department.
What building requirements apply in fire zones?
New construction must meet Chapter 7A of the California Building Code including fire-rated roofing, non-combustible exterior walls, ember-resistant vents, and tempered glass.
Do existing homes need to comply with Chapter 7A?
Chapter 7A applies to new construction and major remodels. Existing homes must maintain defensible space under PRC 4291.
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